How were the days of the week named?

There are seven days in the week, all named for gods.

Sunday is the day of the Sun. Monday is the day of the Moon. Tuesday is the day of Tyr, an ancient German war god. Wednesday is the day of Woden, head honcho of the Norse gods. Thursday is the day of Thor, also a Norse god. Friday is the day of Frieda, Woden’s man squeeze. And Saturday is the day of Saturn, a Roman god.

Sunday and Monday aren’t hard to understand. Sun and moon gods are common in pagan mythologies. But how is that four days are named after German or Norse gods and only one after a Roman god? How did the folks who named the days of the week (whoever they were) settle on four German/Norse gods and one Roman god?

Please hurry with your answers. I’m losing sleep.


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The names of the days of the week were originally Roman, but were changed to Germanic equivalents by Germanic peoples. Apparently,

Sun = Sun
Moon = Moon
Mars = Tiw
Mercury = Wodin
Jupiter = Thor
Venus = Frigga
Saturn = Saturn?

The equivalency must be astronomical or maybe even meaningless, because it surely hasn’t to do with the particular god’s domain. The messenger of the Roman gods does not equate to the king of the Norse gods. Thor is no king of the sea. Frigga ain’t no Venus.

Why didn’t they translate Saturn? I don’t know. Perhaps because they had even less of an equivalent to Saturn in the Norse pantheon. Perhaps because they had already run out of gods they cared about by the time they got to it.

Corrections to Johnny Angel’s mostly right post:

Jupiter isn’t the god of the sea, he’s king of the gods. And Thor was the most important Norse god. So Jupiter’s day=Thor’s day

Friday was also attributed to Freya, a Norse fertility god, like Venus was a Roman fertility god.

And lastly, Woden was a holder of knowledge, wiseman-god. Mercury, besides being a messenger, was also god of sacred mysteries and hidden things.

Other than those corrections, Johnny had it.


The equivalencies are better than indicated above.

The Jupiter/Thor (or Donar) association is because of the thunder/lightning connection they have.

Tiu/Tyr for Mars is a pretty good match; both of them are war gods. Of course, about half the Norse pantheon is connected with war or battle or strength or valor or courage or something like that, so you could make a case for one of them instead… but Tiu isn’t an obviously WRONG choice.

IIRC, Friday is named after Freya/Freyja, not Frigga. Freya is more or less equivalent to Venus.

Woden/Wotan/Odin… okay, this one is sort of a stretch. However, Mercury’s status as messenger connects him with the idea of communication, and Odin is connected with the discovery/invention/revelation of runes through a vaguely Prometheus-like legend. It’s probably the best they could do, since I don’t think Norse/Teutonic mythology had any exact equivalent of Mercury.

By “above”, I meant in Johnny’s post, not in John’s.

And if you equate Jupiter and Thor, the obvious candidate for Saturn would be Odin, who’s already been used. I can imagine whoever was in charge of this throwing up his hands and saying “Heck with it, Saturn’s Day it is.”

All I know about the Norse gods I read in Marvel Comics.

Fascinating stuff, people. I may not believe there are any gods, but the stories are wonderful.

Those who do not learn from the past are condemned to relive it. Georges Santayana

Well, that’s what I get for not checking my facts. :.)

In any case, among the things I don’t know, I don’t know any Norse equivalent to Saturn.

Scandinavian equivalent to Saturn is perhaps Volvo?

The above posts got it pretty much right. but leave out a major part of it.

The names for days of the week have their origins in astrology. In ancient astrology, there were seven movable objects in the sky: the sun, the moon, Mercury, Venus, Mars, Jupiter and Saturn. Each object had its “day of power.”

That’s why the days are named after the gods they’re named after, with Norse equivalents used for four of the familiar Roman names for the planets.

Chaim Mattis Keller

“Sherlock Holmes once said that once you have eliminated the
impossible, whatever remains, however improbable, must be
the answer. I, however, do not like to eliminate the impossible.
The impossible often has a kind of integrity to it that the merely improbable lacks.”
– Douglas Adams’s Dirk Gently, Holistic Detective

see for full story

from that site:
The Romans gave names to the days of the week based on the sun, the moon and the names of the 5 planets known to the Romans:


These names actually carried through to European languages fairly closely, and in English the names of Sunday, Monday and Saturday made it straight through. The other four names in English were replaced with names from Anglo-Saxon gods. According to Encyclopedia Britannica:
“Tuesday comes from Tiu, or Tiw, the Anglo-Saxon name for Tyr, the Norse god of war. Tyr was one of the sons of Odin, or Woden, the supreme deity after whom Wednesday was named. Similarly, Thursday originates from Thor’s-day, named in honour of Thor, the god of thunder. Friday was derived from Frigg’s-day, Frigg, the wife of Odin, representing love and beauty, in Norse mythology.”

The site also explains the names of the months.

For what it’s worth, Tacitus, the chief Roman writer on the Germans, says that Wotan is the equivalent of Mercury/Hermes. He might have based it on astronomy/astrology – he almost certainly did not base it on the 7-day week.

Or something strange may have happened to the German religion in the centuries between his time and our earliest solid records of the German mythology.

John W. Kennedy
“Compact is becoming contract; man only earns and pays.”
– Charles Williams

IIRC, some of the other European cultures have names for days of the week that are much more “Christian” than do the English and Germans; “Sunday” in Spanish-speaking countries is “Domingo”, or “The Day of the Lord”. (Correct me, someone, if I’m wrong, but I don’t think I am.)

The months of the year are interesting, too, and much more Roman than the Norse-derived days of the week:

January=Janus, Roman god of doorways and arches

February=Februa, Roman festival of purification

March=Mars, Roman god of war

April=“aprire”, “to open”; (apparently because it rained a lot in Rome in April)

May=Maia, Roman fertility goddess

June=Juno, Roman goddess of marriage

July=Julius Caesar

August=Augustus Caesar

September, October, November, December=Seventh, Eighth, Ninth, and Tenth; because the Roman calendar started in March, not January, IIRC.

Another interesting factoid concerning our present calendar is that February, July, and August all originally had 30 days each. Julius Caesar and Augustus Caesar each swiped one day from February and added it to the month named after them so they could have the presitige of having a “long” month, and thus, of course, threw the whole thing out of whack and bringing into existance the need for leap years to correct the problem their arrogance created. Nifty, eh?

It is funny that this comes up from time to time. Essentially, this was my first question for the SDMB some years ago. I titled the thread "Was Venus the original ‘Girl Friday?.’

“Why have most western languages adopted the Astronomical names for Saturday, Sunday and Monday (Saturn, Sun and Moon respectively) and yet chose different origins for the remaining days?
Also, if anyone can shed light on the other origins in cultures that were isolated from Latin and Saxon influence, I would be greatly interested.” --Me

In my research around the web, I was able to piece together the following table (with the origins at the end of each line).

Saturn Sun Moon Mars Mercury Jupiter Venus -Astro.
Saturni Solis Lunae Martis Mercurii Jovis Veneris -Latin
Saturday Sunday Monday Tuesday Wednesday Thursday Friday -English
Saterne’s Sun’s Moon’s Tiw’s Woden’s Thor’ Frigg’s -Saxon
Samedi Dimanche Lundi Mardi Mercredi Jeudi Vendredi -French
Sabado Domingo Segunda Terca Quarta Quinta Sexta -Portugese
Sabado Domingo Lunes Martes Miercoles Jueves Viernes -Spanish

From the chart, you can see that the Latin, French and Spanish followed the Astronomical format, while the English and Saxon followed a hybrid of Astro/Mythological. I find it particularly interesting that the Portugese carried the Astrological for the weekend and then simply started numbering the days.

Here is some background into the way in which the order developed. Rather than chart the whole thing in this posting, I will leave it to those who are interested to try it at home.

First, the order of the planets came from the duration of their Orbit, as viewed from Earth. In descending order, this gives us Saturn = 10,761 days, Jupiter = 4,332 days, Mars = 687 days, Sun = 365 days, Venus = 224 days, Mercury = 88 days, Moon = 29 days.

With this order, each of the hours in each of seven days is given a planet. Start at 1:00am Saturday with Saturn, 2:00am with Jupiter and so on. When you get to Midnight with Mars, the Sun is carried over to 1:00am Sunday. This continues until you have the days filled in, with 1:00am each day representing the name of the day as the Romans would have called them.

My conclusion (admittedly far from truly satisfying) was that the Saxon’s had attached meaning to Saturn, the Sun and the Moon, but felt that Tiw, Woden, Thor and Frigg were more significant (to them) than the remaining ‘wanderers.’

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So how does Stephen claim ‘Domingo’, in Portuguese is an astonomical name, when it’s Latin for ‘lord’?

On quite another tack, if the Norse or their predecessors waited around until the Roman’s could hand them names for days of the week, does that mean they didn’t have weeks, but only maybe a lunar months, whose days, I assume were just numbered?

And how does Pickman’s Model ever figure that exchanging days between different months has anything to do with adding leap days in certain years? The latter is a result of there being an extra fraction of a day beyond 365 in a solar/seasonal cycle (true year) – nothing to do with the greed of the Caesars.


Yeah, Pickmans got a few minor errors in his post.

First there were originally (not sure on too much that occurred before the Roman empire) 10 months. It didn’t start in March, the year lacked the two months July and August, and therefore the final 4 months names make perfect sense. The Ceasars did however steal a day from February to make their months longer. It around the same time that the monks (who mostly were responsible for the intellectual stuff like time keeping, and standards) developed a accurate length for the solar year, and saw the need for more months facilitating the Ceasar’s additions. Shortly after they came to the conclusion that they were still 8 days short. And hence added the additional days to the appropriate months. Finally the need for a leap year was realized (when I’m not sure) because the solar cycle is ~365.25 days. (As well as a variety of additional added days which have been discussed in another thread, and column IIRC) The leap year had nothing to do with the Roman calender, the Roman calender was a huge advance and something we should be eternally greatful for, and it makes a hell of alot more sense that the 7 day week and the names of the days.

It is absolutely false that the primitive Roman calendar lacked July and August. They were there, called Quintilis and Sextilis. It is January and February that were added later (at least according to legend, which is all we have).

The story that Augustus stole a day from February to make his month longer appears to be no older than the middle ages. July was not named for Julius Caesar until after his death, so he couldn’t have done it.

“Monks” had nothing to do with Caesar’s reforms. He was himself, technically, the High Priest of Rome, and decided to clean up a job associated with his office that had gotten hopelessly dirty. The figure 365.25 he got from an Egyptian astronomer, one Sosigenes. (The Egyptians had been aware of the number for a very long time, although they used a 365.0-day calendar, and just had a big party every 1461 years when the odd quarter day came out even again.)

I cannot figure out what this is intended to mean:

If, by “Roman Calendar” you mean Caesar’s Julian Calendar, it has everything to do with leap years; it was Caesar’s reform that put them in. If, on the other hand, you mean the Roman Calendar before Caesar, it was one of the most ghastly, chaotic, corrupt, and inaccurate calendars in human history.

John W. Kennedy
“Compact is becoming contract; man only earns and pays.”
– Charles Williams

I stand corrected. I was taking my information from another source which was obviously wrong. (But then, I never claimed to be omniscient.) As for solar years and other astronomical jazz, I’ll have to take your word for it, since astronomy is 90% higher math, which I avoid like the plague, since it is a curse upon humankind designed to drive men mad. (It works, too.)
My apologies for the spread of any misinformation. :slight_smile:

As Stephen indicated:

Saturn Sun Moon Mars Mercury Jupiter Venus -Astro.
Saturni Solis Lunae Martis Mercurii Jovis Veneris -Latin
Saturday Sunday Monday Tuesday Wednesday Thursday Friday -English
Saterne’s Sun’s Moon’s Tiw’s Woden’s Thor’ Frigg’s -Saxon

Was “Saterne” the Saxon word for Saturn, the a visible heavenly object (or did they figure that one out from the Romans)?
Samedi Dimanche Lundi Mardi Mercredi Jeudi Vendredi -French

Sabado Domingo Segunda Terca Quarta Quinta Sexta -Portugese
Sabado Domingo Lunes Martes Miercoles Jueves Viernes -Spanish
I can’t help but be in awe of the Portugese idea of naming the days after Sunday just plain “second, third, fourth…”; German pitches in timidly with “Mittwoch” for Wednesday.

You may notice that the romance languages got Sun-day transformed into “the Lord’s Day”> Dies Domini> Domingo. But notice the Iberians’ naming of the 7th day: “Sábado”. Either that’s some serious transposition of consonants, or got loaned from yet another religious tradition.


Of course, astronomical vs. mythological is a false dichotomy because the planets themselves were named after gods. Sol and Luna were a god and goddess in the Roman tradition.

If you’re interested, not that you are, the Esperanto words for Sunday through Friday are from the French (dimancho, lundo, mardo, merkredo, jhaudo, vendredo). However, Saturday is sabato from the Spanish. Oddly, this is also the word for Sabbath, whether Saturday or Sunday. Moreover, we also have the word “shabato”, which is “sabato” with a circumflex on the s; it refers to the Jewish Shabbat or to Wiccan sabbats (Imbolc, Ostara, Beltane, Midsummer, Lughnasadh, Mabon, Samhain, and Yule).

There are a pair of good articles about the evolution of our calendar at and